J. Phys. Ther. Sci. 28: 1574–1576, 2016

The Journal of Physical Therapy Science Original Article

Trekking poles reduce downhill walking-induced muscle and cartilage damage in obese women Su Youn Cho1), Hee Tae Roh2)* 1) Exercise

Physiology Laboratory, Department of Physical Education, Yonsei University, Republic of Korea of Physical Education, College of Arts and Physical Education, Dong-A University: 37 Nakdong-daero, 550 beon-gil, Hadan-dong, Saha-gu, Busan 604-714, Republic of Korea

2) Department

Abstract. [Purpose] This study investigated the effect of the use of trekking poles on muscle and cartilage damage and fatigue during downhill walking in obese women. [Subjects and Methods] Subjects included eight obese women who had a body fat percentage greater than 30. Subjects performed downhill walking without a trekking pole (NP) and with a trekking pole (TP) at 50% heart rate reserve for 30 minutes on a treadmill. The treadmill was set at a 15% downhill declination. Blood samples were collected to examine muscle damage (serum creatine kinase [CK] and lactate dehydrogenase [LDH] levels), cartilage damage (serum cartilage oligomeric matrix protein [COMP] levels), and fatigue (plasma lactate levels) at the pre-walking baseline (PWB), immediately after walking (IAW), and 2 hours post-walking (2HPW). [Results] The CK, LDH, COMP, and lactate levels were significantly increased IAW when compared with those at the PWB in both trials. In addition, in the NP trial, the CK, LDH, and COMP levels were significantly increased at 2HPW when compared with those at the PWB. [Conclusion] Downhill walking can cause muscle and cartilage damage, and our results suggest that the use of a trekking pole can reduce temporary muscle and cartilage damage after downhill walking. Key words: Trekking pole, Muscle damage, COMP (This article was submitted Jan. 5, 2016, and was accepted Feb. 2, 2016)

INTRODUCTION Walking is one of the recommended modes of exercise for obese individuals because of its merits in terms of safety, accessibility, and popularity, as well as proven efficacy in weight management1, 2). However, walking over a terrain of repetitive uphill and downhill inclines in activities such as mountain climbing can cause excessive fatigue and muscle damage3). In particular, repetitive eccentric contractions of the lower limb muscles during downhill walking places sarcomeres under excessive tensile stress. This stress can destroy sarcomeres by extending them beyond their normal length, sometimes involving a local inflammatory reaction, and can thereby lead to delayed onset muscle soreness or exercise-induced muscle damage. The indexes reflecting such conditions are serum creatine kinase (CK) and lactate dehydrogenase (LDH) levels4, 5). It has been reported that the use of a pole during walking over an uneven terrain could improve gait stability and balance, and that its use during downhill terrain walking can reduce the load and stress on the lower limbs (such as the ankle, knee, and hip joints)6–8). However, previous studies on the effects of a pole during downhill walking have been limited to the kinetic aspects such as the reduction of knee joint forces or the load on the lower extremity joints. Meanwhile, it has been suggested that increases in peripheral cartilage oligomeric matrix protein (COMP) levels after exercise could serve as a biomarker of cartilage degradation and damage9), and Pruksakorn et al. reported significant increases in serum COMP levels after uphill walking10). In addition, according to a comparative study by Andriacchi et al. that measured the maximum flexion of the lower extremity joints during various routine activities, the flexion of the knee joint was approximately 4 times greater during walking down stairs than during walking over level ground11). Taken together, such previous reports suggest that the use of a pole during downhill walking may alleviate the burden on lower extremity joint *Corresponding author. Hee Tae Roh (E-mail: [email protected]) ©2016 The Society of Physical Therapy Science. Published by IPEC Inc. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives (by-nc-nd) License .

cartilages; however, thus far, there has been no report examining this potential benefit. Accordingly, this study aimed to investigate the effect of the use of a trekking pole on muscle and cartilage damage and fatigue during downhill walking. The study specifically examined obese women who had less muscle mass than men and whose heavy weights were likely to increase the burden on their lower limb muscles and joints during walking.

SUBJECTS AND METHODS Eight obese women (average age of 21.1 ± 1.8 years, average height of 164.8 ± 4.9 cm, average weight of 61.8 ± 7.7 kg, average body fat percentage of 33.9 ± 1.4%, and average resting heart rate of 69.6 ± 3.7 beats/min) with body fat percentages ranging from 30.0 to 36.1 volunteered as subjects for this study. The study conformed to the standards set by the latest revision of the Declaration of Helsinki, and all subjects read and signed a written informed consent statement consistent with the guidelines of the Department of Physical Education at Yonsei University. Anthropometric measurements included height, body composition, and resting heart rate. Height and body composition were measured using a stadiometer (SECA213; SECA, Hamburg, Germany) and a bioimpedance analysis (BIA) device (Inbody720; Biospace, Seoul, Korea), respectively. Resting heart rate was measured in a seated position using a heart rate monitor (Polar a5; Polar, Kempele, Finland). Each of the eight subjects participated in a total of two trials: one NP trial (walking without using a trekking pole), and one TP trial (walking using a trekking pole). With the treadmill angle set to a decline of 15% based on a study by Perrey and Fabre12), the participants were subjected to 30 minutes of walking at an exercise intensity of 50% of their heart rate reserve. The experiment used a crossover design to minimize the adaption from the repetitive exercise trials, and each trial was separated by 7 days to avoid any transient effects on the physiological and psychological conditions of the subjects. An adjustable-length trekking pole (6342011; LEKI, Hamburg, Germany) was used, and the length was initially set at 70% of the user’s height so that the elbow angle was maintained at 90° when the user was standing on level ground. When the pole was used for downhill walking, its length was increased by approximately 5 cm. Using a 22-gauge needle, a serum separator tube (Becton Dickinson, Franklin Lakes, NJ, USA), and a ethylenediamine tetra-acetic acid tube (Becton Dickinson), 7 ml of blood was collected from the antecubital vein of each subject at the prewalking baseline (PWB), immediately after walking (IAW), and 2 hours post-walking (2HPW). Collected blood samples were centrifuged for 15 minutes at 3,000 rpm and then stored at −80 °C until analysis. The serum CK and LDH levels were determined using a clinical chemistry analyzer (Ektachem DTSCII; Eastman Kodak, Rochester, NY, USA). The serum COMP levels were determined with an enzyme-linked immunosorbent assay (ELISA) using a commercially available Human COMP® ELISA kit (AnaMar AB, Lund, Sweden). The absorbance was measured at 450 nm with a microplate reader (Molecular Device, Palo Alto, CA, USA). The plasma lactate levels were determined using a clinical chemistry analyzer (Ektachem DT 60; Eastman Kodak, Rochester, NY, USA). Statistical analyses were performed with SPSS version 21.0 for Windows (SPSS Inc., Chicago, IL, USA). Data are presented as the mean ± standard deviation (SD) unless otherwise stated. For identifying differences in normally distributed results, two-way repeated analysis of variance (ANOVA) was employed. When significant group by time interactions occurred, simple main effects were assessed using one-way ANOVA and independent t-tests. Levels of significance were set at p=0.05.

RESULTS The biomarker levels measured are presented in Table 1. The serum CK, serum LDH, serum COMP, and plasma lactate levels were significantly increased IAW when compared with those at the PWB in trials NP and TP (p

Trekking poles reduce downhill walking-induced muscle and cartilage damage in obese women.

[Purpose] This study investigated the effect of the use of trekking poles on muscle and cartilage damage and fatigue during downhill walking in obese ...
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